Studies On Various Treatment Conditions Affecting Urea-Ammoniated Rice Straw In Ghana

A B S T R A C T

Four experiments were undertaken to evaluate the e f fe c t

of various treatment conditions on the nu tr itiv e value of

urea-ammoniated r ic e straw.

Experiment 1 was carried out to determine the optimum

condtions necessary fo r ammoniating r ic e straw with urea. The

factors investigated included urea concentration (3 .5 , 4.0, 6.5

and 8.0% W/w), treatment period (7, 14 and 21 days) and

moisture le v e l (40, 50 and 60%), in a 4 x 3 x 3 fa c to r ia l

experiment.

Samples were analysed fo r t o ta l Nitrogen content,

neutral detergent fib r e (NDF), acid detergent f ib r e (ADF) and

in v it r o organic matter d ig e s t ib i l i t y (IVOMD). Results showed

that the optimum urea concentration, treatment period and

moisture le v e l ware 6.5%, 21 days and 40% re sp e c tiv e ly .

In Experiment 2, the optimum conditions obtained in

Experiment 1 were used to treat r ic e straw which was then

stored in d iffe r e n t types o f s i lo (earthern p i t , cane basket

and cement cu lv e r t) to determine the best s ilo to use. The

earthern p it was found to be the best among the s ilo s with i t s

contents having a N content o f 1.75% and IVOMD 52.65. Straw

from the basket and culvert had 1.55% and 1.10% N and 50.03 and

t

48.21 IVOMD respec tiv ely .

The in situ rate of ruminal dry matter (DM)

I ,

disappearance (DMD) (3-72h) and extent o f DM disappearance

(72h) investigated in Experiment 3 indicated that urea ammoniated straw was more fermentable In the rumen o f sheep

compared with untreated r ic e straw. The rate and extent o f DMD

was found to be 0.48%/hr and 44.64% fo r untreated r ic e straw

and 0.74%/hr and 58.97% fo r ammoniated r ic e straw.

Urea treatment s ig n ific a n t ly increased straw intake but

did not prevent sheep freight los s in Experiment 4.

Straw ensiled with urea fo r 21d and fed to sheep with

l i t t l e supplementation can supply maintenance needs o f

ruminants during the dry season.